docs: async def call_with_fd_list(proxy, method_name, signature, args, fds,
                              flags=0, timeout_msec=-1):
      """
      Asynchronously call the specified method on a DBus proxy object.
  
      :param Gio.DBusProxy proxy:
      :param str method_name:
      :param str signature:
      :param tuple args:
      :param list fds:
      :param int flags:
      :param int timeout_msec:
      """
      future = Future()
      cancellable = None
      fd_list = Gio.UnixFDList.new_from_array(fds)
      proxy.call_with_unix_fd_list(
          method_name,
          GLib.Variant(signature, tuple(args)),
          flags,
          timeout_msec,
          fd_list,
          cancellable,
          gio_callback,
          future,
      )
      result = await future
      value, fds = proxy.call_with_unix_fd_list_finish(result)
      return pack(*unpack_variant(value))